[boost] [property_map] test program fix.

The following fix gets the property_map test that's currently failing with several high-quality compilers, building OK (at least with vc7.1, I can't test with MWCW, but that compiler has the same issue with the existing test so it should fix it). Is this OK to commit? John. diff -r1.1 dynamic_properties_test.cpp 110c110 < BOOST_CHECK(get<std::string>("nada",props,std::string("3.14")) == "pi"); ---

BOOST_CHECK(get("nada",props,std::string("3.14")) == "pi");